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### Use of Hyphen When Writing Fractions with Words

Date: 01/20/2004 at 10:08:45
From: Colleen
Subject: Writing fractions in word form

Is there one correct way to write a fraction in word form?  I have
seen one-half and have also seen one half.  I have seen 2/3 written as
two-thirds or as two thirds.  Are both ways (with a hyphen, without a
hyphen) acceptable, or is only one truly correct?

Date: 01/20/2004 at 13:15:46
From: Doctor Peterson
Subject: Re: Writing fractions in word form

Hi, Colleen.

I usually reserve the hyphen for use in keeping the name of the
denominator together.  For example,

1/5 = one fifth

1/25 = one twenty-fifth

2/100,000 = two hundred-thousandths

200/1000 = two hundred thousandths

But you will also see hyphens within numbers when the entire number
is used in certain special settings:

One third of a piece

A one-third share

A hundred thousand dollars

A hundred-thousand-dollar income

That may be what you have seen.

Writing Numbers with Hyphens
http://mathforum.org/library/drmath/view/63129.html

Written Form of Decimals
http://mathforum.org/library/drmath/view/58968.html

On the other hand, a web search reveals lots of writing style guides
that seem to recommend always using the hyphen in fractions, without
making a distinction as to usage.  Here is just one of many examples:

http://owll.massey.ac.nz/writing/grammar_punctuation/hyphen.htm

Any two numbers or fractions that are written as words are
hyphenated.

When she reached the age of twenty-one, Sylvia inherited
three-quarters of a million dollars from her trust fund.

This page doesn't give an example of a fraction, but does clearly
explain why you use hyphens in the cases I showed above, called
"compound modifier".  An example is

a woman-hating religion is utterly different from a woman
hating religion

Here, finally, is a page that ALMOST agrees with me:

http://www.bewrite.net/community/tips/atg_hyphenating_numbers.htm

There is some controversy, though, over whether or not to
hyphenate fractions like three-fourths.  Some sources say to
hyphenate fractions always and others say to hyphenate them
only when using them as an adjective, as in a one-half owner.
I say, keep it simple, stupid: if you always hyphenate
fractions when writing them out, you have fewer rules to
remember.

"Is a fraction always hyphenated?  No, it is not. A hyphen is
not used with a fraction that is not serving as an adjective.
'Today he paid one half of the tax,' not one-half."
-- The Wordwatcher's guide to Good Writing and Grammar

Here is another site that says not to hyphenate all fractions; but it
somehow turns the rule on its head just where it is most needed:

Hyphenation: Consult the Chicago Manual of Style.
...

Fractions and hyphens:  Fractions are almost always hyphenated

e.g., "He is one-quarter Irish and three-quarters Nigerian."

But when the numerator is already hyphenated, the fraction
itself is not, as in "ninety-nine and forty-four one
hundredths."

Fractions treated as nouns are not hyphenated.

e.g., "He ate one quarter of the turkey."

So both rules are to be found, but the best reason for always using
hyphens is just to make it easy for people to remember the rule!  I
still say our rule is best when you want to make sure every case will
be understood; but then, grammar is not math (obviously!).

If you have any further questions, feel free to write back.

- Doctor Peterson, The Math Forum
http://mathforum.org/dr.math/
Associated Topics:
Middle School Fractions

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